Effect of Weld Lines on Injection Moulded Fibreglass Reinforced Structural Foams. 1 - Morphology, Shear and Tensile Properties

In this work, the effect of weld lines and density reduction on the morphology and mechanical properties of injection moulded fibreglass reinforced polypropylene structural foams is reported. In this first part, cell size, cell density, skin thickness as well as tensile and shear mechanical properties are reported. As expected, all mechanical properties decreased with density reduction. On the other hand, the presence of a weld line produced a more complex behaviour: lower tensile properties with higher torsion modulus. These results are shown to be related to a change in fibre orientation along the sample length which is the main factor controlling the mechanical response of these composite foams.